I'll Protect You Forever
by NebulaWrites
Summary: Yei and Coulomb are in Amestris and decide to get something to eat in the town of Rush Valley. Yei goes running around a bit but after jumping off a stack of boxes she lands on someone's head. After leading the person around on a fruitless chase she and Coulomb meet up and go to the train but Yei is caught and misses the train. What happens next? Ling x OC; AU. T for language
1. First Meetings and Missing the Train

_O_O hi. XD what i was thinking when i wrote this, i have no idea all i knew is i wanted a Ling x OC story where the OC jumps on Ling's head. so yeah XD_

 _Disclaimer: i don't own FMA:B or it's characters. i own Yei but not Coulomb because legit Coulomb is a real character._

* * *

It was a relatively cool day and two very obvious Xingese teens were standing in front of a shop waiting for the shop owner to bring out their food. "Coulomb." The girl whined making the boy look over, "Patience. If you're just going to whine about it then go run around a bit, work up an appetite." Coulomb said and the girl whined again, "I can't work up much more of an appetite."

Coulomb glared at her and the girl turned around on her heel and ran off, glancing back over her shoulder every once and a while. With a sigh she ran up a pile of boxes and jumped off, landing squarely on someone's head bending her knees and extending her arms to her sides to keep her balance.

Slightly confused she jumped off and landed on the man in armor, who sat across from the one she's landed on. "What are you?" she asked with a tilt to her head as she crouched down to look at the man's helmet. When she felt two new presences behind her she jumped to avoid two kunai before landing on the armor again.

With a smirk she hooked the helmet on her foot and kicked it into the air before roundhouse kicking it at the two. "Yei, come along!" Coulomb called as he began darted past, Yei hummed a little before jumping off the armor and running after him. "Get back here!" a voice yelled and Yei turned around briefly before squeaking and running quicker, grabbing Coulomb's arm as she passed.

"Run!" she cried before giggling, "Yei who did you piss off this time?" Coulomb demanded as he too began running faster, not bothering to look over his shoulder.

"Hmmmm, dunno. Jumped off some boxes and landed on someone's head then I jumped on a man in armor, who honestly doesn't have a flow of chi, which creeps me out. Then two people tried to attack me and I kicked the armor's helmet at them then ran after you as you passed."

Coulomb gave her a somewhat angry glare before he said, "You need to learn to watch where you go because then we wouldn't be getting into fights every day and using most of our money on buying medical supplies!"

Yei giggled before letting go of his arm to stop, pull a pin on a flash grenade and throw it at the four chasing them. "Split up. I'll meet you back at the rendezvous point." She said as she ran past Coulomb, the elder teen gave her a glare before running off down an alley to the right. The younger teen giggled and whistled to get the attention of her pursuers, "Catch me if you can!"

With another giggle she was off, humming as she ran. Soon she used a few men as steps to climb up onto a roof. Giggling more when she heard frustrated groans Yei increased her speed.

Soon the urge to run along the edge of the building won out and she stepped up onto it before extending her arms to the side before running more. Suddenly a teen dropped in front of her, sword drawn and expression nothing short of angry.

Yei stopped and tilted her head to the side cutely before saying, "Took you long enough."

The teen was visibly confused but that just made Yei giggle more, "Too late though~." She sang before running towards him, her knife in hand but hidden behind her, "Yei do not harm him just come along!" Coulomb's voice snapped making her freeze before sighing and turning to jump off the building.

Coulomb grabbed her hand and pulled her up on the building he was on. "If we don't hurry we'll miss our ride and the food will spoil." He grunted and Yei hummed as she began following the elder teen chirping out a cute 'okay'.

"Why didn't you want me to hurt him?" she asked eventually and Coulomb grunted, "Long story but to put it simply I know him and he may or may not remember me." He stated and Yei frowned.

They reached the train station and Coulomb paid for their tickets as Yei began eating her food. "Not nearly as good as the food back home but it's still yummy." She said as she began following the elder teen when he walked towards the train, he glanced at her over his shoulder. "They surely do not have the herbs that we have back in Xing so that is sensible." He pointed out and she nodded in both agreement and in time with her step.

"Come on," Coulomb said. "Be any slower and the train will leave without us."

Yei giggled and picked up her pace to catch up with Coulomb as he climbed onto the train. She spotted a garbage can and rushed over to put her empty food container in there before darting back to the train and up onto the steps. But a hand grabbed her hair and yanked hard.

With a cry she stumbled back onto the platform, "Coulomb!" she cried, as the train started moving, Coulomb poked his head out the window and his eyes widened. "Yei!" he shouted before ducking back into the train and running down the isle to try and get to the door.

"Coulomb," Yei cried again. "Help me!"

The elder teen got to the end of the train and stared back at the platform as the train took off, "YEI!"

Yei reached towards Coulomb helplessly, " _COULOMB_!"

"Fu," a voice shouted. "Let her go this instant!"

Instantly the grip on her hair was gone and without any thought she ran but all that happened was she ran right into a person. Teary-eyed she pulled back and took frantic retreating steps.

"I-I'm sorry," she stammered. "I-I didn't mean to land on your head, please just let me go all I want to do is get out of here." The teen from the roof looked down at her with a somewhat concerned expression. "You don't need to apologize," he said. "I could've chosen a better spot to sit and it should be me apologizing for my vassal making you miss your train."

Yei could only look down the track to the retreating train. "By the name of the Western Sage how will I pay for another ticket for the next train? He had all the money…" she said to herself before whimpering and letting her shoulders sag. This was going to be interesting.

* * *

 _hehehehe :3 review if you like! no review no next chapter(or i might put one up just because XD) and how Yei and Coulomb met will be explained in the next chapter._


	2. Talking and Learning Names

_chapter two already because i'm in the mood to update this fic XD don't judge me! oh and i never got to explaining how Yei and Coulomb met so that'll be in the next chapter hopefully O_O_

 _Disclaimer: this again? XD i only own Yei and her rather bizarre personality O_O everyone else belongs to Hiromu Arakawa_

* * *

Yei could only stand there with a pouting expression as the teen and the two masked figures talked. But out of nowhere a boot was thrown at her and she didn't have a chance to dodge so it hit her square in the face. "OW! What the hell?!" she shouted as she threw the boot back at the blonde who caught it then threw it at her once again.

This time Yei ducked and hid behind the teen from the roof. "Brother stop!" a voice shouted and she yelped as the blonde tackled her, "Ed!" the teen nearly shouted as the blonde and Yei fell onto the tracks.

Furiously she kicked the blonde in the stomach before scrambling to her feet to climb back up onto the platform. The teen helped her up before grabbing the blonde's arm and pulling him up with ease.

"What the hell's your problem," Yei hissed. "Pipsqueak?"

The blonde yelled furiously at that and moved to attack her but with long practiced skill she dodged his fists. But eventually she backed into someone and the teen sighed, raising one hand to block the blonde's punch. "I take it you have a very limited fuse when it comes to your height being mentioned." He sighed and the blonde growled and ripped his hand free.

Yei pouted and quickly ducked around the teen before beginning to walk away. "You have to pay for my new train ticket." She stated glaring at the teen and blonde over her shoulder before sitting down on a bench. "Young lord you shouldn't let her speak to you in such a disrespectful manner!" the one with the mask that had the white ying-yang symbol nearly shouted and the teen sighed.

"Fu," the teen looked at the man. "It was our fault that she missed her train you realize."

Fu stiffened in obvious surprise and Yei decided to finally actually take in each of their appearances. The blonde was short, his hair was braided, he had a mechanic arm and he was wearing black clothes and shoes. In her opinion that should overheat any person too quickly.

The teen had long black hair styled in a ponytail with his bangs hanging over one eye, he had a golden jacket with white trimming, he had no shirt, he was muscular, he had white baggy pants and white gauze around his wrists and waist. But one thing that had her stumped was his closed eyes, how on earth could he walk around without running into things? Plus where was his sword that he had when he dropped in front of her?

"Hey," she said. "What are your guys' names?"

The teen looked over before pointing at the masked figures, "They are Lan Fan and Fu. The blonde is Edward, the one in armor behind Edward is Alphonse and I'm Ling Yao."

Yei put her hands together and bowed, "Yei Zen." She replied before studying Ling slightly, "You're from Xing, obviously, but you said your last name was Yao, do you have a brother?" she asked and Ling blinked, "I have many brothers."

She shook her head at that, waving her hand slightly, "No, I mean a brother that shares your name Yao." She explained and Ling nodded slowly, "I do but no one knows where he is." He stated and Yei propped her head up on her hand with a smirk. "I did. And if I'm right I still do."

Ling seemed to freeze in shock, "You know where Prince Coulomb is?" Fu demanded and Yei giggled as she shrugged, "Maybe, maybe not. It all depends on if he jumped off the train to come back but probably not knowing him. He's probably still on his way to our next rendezvous point."

Ling rushed over and grabbed her shoulders frantically, "You have to tell us where that rendezvous point it! I must speak with him!"

"I can't," Yei said. "If I'm not there five minutes after he gets there then he'll just continue on without me and if I do not know where the rendezvous point after the next one is then the chances of finding him are slim to none."

Ling turned to Edward quickly, "Buy us tickets for the next train and I will repay you later." He said and Edward turned around and began walking away, Alphonse looked at them before following. "Edward! I'll even repay you for the meal and whatever damage Lan Fan caused your automail!"

Edward turned around at that, "I'm not buying some spoiled brats tickets for the damn train!" he shouted and Lan Fan ran at him with a kunai out, "Lan Fan stop!" Ling ordered and the masked form stopped.

"Please Edward," Yei pleaded. "I must meet up with Coulomb, if I do not and he gets stopped by a military patrol he'll be put in jail because I have our passports!"

Edward growled at that and glared at Yei with blazing eyes, "Why should I?" he asked and Yei took a deep breath, "Because if you don't I will start shouting what your brother is at the top of my lungs." She threatened and the blonde's eyes went large with anger.

"You wouldn't dare."

She lifted her chin as she stood, her deep blackish purple eyes glittering confidently. "Try me."

The two stared each other down for a while before Edward growled and began walking towards her. "It's not like the tickets to Central are all that expensive." She pointed out and the blonde suddenly turned around on his heel. "If you're going to Central then you can wait for Al and I." He stated and Yei began storming after him, "I cannot do that I simply do not have the time!"

"Suck it up and wait!"

"I told you I couldn't! Get back here and buy us tickets!"

* * *

 _XD what am i even doing with this? i have no idea! i've decided to post new chapters for this whenever i can XD so yeah with this fic you'll just have to be patient_


End file.
